Guo Wengui — the Chinese billionaire accused of treating his personal assistant as a sex slave — has been hit with a new slander suit.

Journalist Watson Meng, the Duke grad who founded Chinese-language Web site Boxun.com in 2000, is suing Guo in Manhattan Supreme Court.

The real-estate tycoon, who lives in a $68 million penthouse in the Sherry-Netherland on Fifth Avenue, has become China’s highest-profile fugitive after using social media to blast the Communist Party as a “kleptocracy.”

Guo apparently upset Meng, who prides himself on his journalistic independence, when he allegedly said the writer was “acting as an agent of the Chinese government,” one source said. “It’s the essence of defamation, undermining a news organization.”

Robert C. Angelillo of Arkin Solbakken LLP told me: “Mr. Guo’s attacks on our client, Mr. Meng, reflect a mean-spirited and ironic effort by an alleged corruption whistleblower to retaliate against a newsman who sought to report the truth about him.”

Guo, aka Miles Kwok, fled China in 2015 after what he claims was a politically motivated fraud conviction.

Caixin Media, real-estate development firm Soho China, and HNA Group, a Chinese conglomerate, are some of the other companies suing Guo for defamation.

In September, his former personal assistant, Rui Ma, sued him for rape, claiming he kept her captive with threats to have her jailed and tortured if she escaped his homes in NYC and London. Guo believes that the suits are orchestrated by the Chinese government, which he said is trying to silence him for exposing corruption in his home country.

With President Trump heading to China next week, Guo has been posting photos of his three meetings with Steve Bannon, the Breitbart News baron who was briefly the White House chief strategist.